Such a device is known from German Published Patent Application No. 197 57 760, and it requires two image-taking devices to record the marking devices from two different perspectives. For this purpose, the two image-taking devices are situated laterally at a distance from the passing motor vehicle. An additional marking device is set up between the image-taking devices and the motor vehicle, which is utilized for the evaluation as reference feature device to determine a wheel plane. From the relative position of the wheel plane to the vehicle's motion coordinates it is then possible to determine at least the wheel plane and/or the axle geometry.
German Published Patent Application No. 199 34 864 also shows a device for determining the wheel geometry and/or the axle geometry of motor vehicles, and it also has an apparatus of two image-taking devices. In this instance, additional reference features are situated in one plane, and they are used to ascertain the vertical direction in the inspection room. The position of the wheel's axis of rotation is determined with respect to the vertical and the direction of the axis of travel, which is obtained from the path of motion of the body feature.
Such apparati always require two image-taking devices per wheel, which have to be set in a costly manner to a common measuring space. In addition, there is a great space requirement laterally from the motor vehicle, because of the required distance from the features that are to be recorded.
It is the object of the present invention to improve an apparatus for determining the wheel geometry and/or the axle geometry of motor vehicles of the above-named type in such a way that, in response to a simple measuring construction there comes about a reduction in the entire space requirement for the measuring equipment. Furthermore, complete measurement of the wheel geometry and/or the axle geometry is to be made possible.